Facebook has removed 82 pages, groups and accounts for “coordinated inauthentic behavior” that originated out of Iran.

The social networking giant discovered the “inauthentic behavior” late last week, according to a blog post by the company’s cybersecurity policy chief Nathaniel Gleicher. He said the operation relied on posing as U.S. and U.K. citizens, and “posted about politically charged topics such as race relations, opposition to the President, and immigration.” The company said that although its investigation is in its early stages, it traced the activity back to Iran but does not yet know who is responsible.

Facebook said that a little over one million accounts followed at least one of the pages run by the Iranian actors. The takedown also included 16 accounts on Instagram.

The actors spent “less than $100” on two ads on Facebook and Instagram using both U.S. and Canadian currency, which helped the actors gain a greater reach to Facebook users.

The company shared its findings with the FBI prior to the takedowns, Gleicher added on a call.

It’s the latest batch of account and content takedowns in recent months. Facebook took down hundreds of accounts and pages in August with help from security firm FireEye, which found a widespread Iranian influencing operation on the social media platform. Although previous efforts by Facebook to take down accounts linked with spreading disinformation aimed at elections, the Iranian-backed campaign was targeting a scattering of issues. FireEye said in its analysis that the various narratives employed by the Iranians include “anti-Saudi, anti-Israeli, and pro-Palestinian themes, as well as support for specific U.S. policies favorable to Iran, such as the U.S.-Iran nuclear deal.”

Tech titans like Facebook have faced increasing pressure from lawmakers to better police their platforms from disinformation and the spread of false news from state-backed actors in the wake of the 2016 presidential election.

Although much of the focus has been on activity linked to trolls working for the Russian government, which used disinformation spreading tactics to try to influence the outcome of the election, Iran has emerged as a separate powerhouse in its use of spreading disinformation on the platform.